When subjected to handling or physical and mechanical treatments, notably involving friction, the surfaces of plastic films become charged with static electricity.
This static electricity causes dust to attach to the surface of the film and results in a risk of discharge, sparks or even ignition when the charge becomes high. When the plastic film is used as a support for a photographic product, these phenomena are particularly troublesome in terms of the quality of the final image. This is why numerous substances have been proposed in the prior art for reducing electrostatic charging. These substances are mixed with various carriers or additives in order to produce antistatic compositions which are then applied in layers to photographic supports or products. A review of antistatic agents which can be used in photography can be found, for example, in Research Disclosure No 501, September 1994, Publication 36544, page 520.
The very abundance of the substances cited in this publication and the dates of the references show that it is difficult to find antistatic substances which give full satisfaction. Some substances interact with the components of the photographic product and the image-forming mechanism, others are insufficiently stable or exude layers in the area where they have been incorporated, others are difficult to formulate as they require grinding and dispersion operations involving organic solvents, and finally, many have insufficient effect on electrostatic charging.
The applicant recently discovered a novel substance which is a fibrous inorganic polymer of aluminium and silicon, with antistatic properties. This substance and a method for its synthesis are described in the international patent application WO 96/13459 filed on Oct. 24, 1995 and entitled "New Polymeric Conductive Alumino-Silicate Material, Element Comprising said Material and Process for Preparing it".
The object of the present invention is a novel composite based on an organic polymer and a polymeric alumino-silicate. This material will be referred to hereinafter as an organic/inorganic composite.